Rotating device for rock-drills.



C. 0. PALMER.

ROTATING DEVICE FOR ROCK DRILLS.

APPLICATION FILED AUG.26, 1910.

l l 5 3,700 Patented Sept. 14, 1915.

a o al IMU autor CnLuMBlA PLANoaRAPH co.,WASHxNaTON. D, c.

CHARLES OTIS PALMER, OF CLEVELAND, OHIO.

ROTATING DEVICE FOB. RGCK-DRILLS.

Specification of Letters Patent.

Application filed August 26, 1910. Serial No. 579,165.

To all whom t may concern.'

. Be it known that I, CHARLES Oris PALMER, a citizen of the United States of America, residing` at Cleveland, in the county of Cuyahoga and State'of Ohio, have invented certain new and useful Improvements in RotatingV Devices for Rock-Drills; and 1 hereby declare the following to be a full, clear, and eXact description of the invention, such as will enable others skilled in the art to which it pertains to make and use the same.

My invention relates to rock drills and tools of similar nature and has for its object to provide a rotating device which shall exert sufficient force to rotate the drill under normal working conditions, but will avoid breaking the tool, in Vcase it should require abnormal force for its rotation as is sometimes the case.

One of the best means for rotating a drill of this class, has been found to consist of a ride-bar suitably associated with the reciprocatory piston, but hitherto the means employed for retainingthe rifle-bar itself ieldinoi against rotation has been b some LS b friction drive that was variable in its action unless'altered occasionally by manual adjustment. To gain access to this adjustment when inclosed, required the removal of the cover with lits air tight joint. Or else thepacking of the stem to prevent the escape of the air where the adjustment was outside the shell. By my invention the spring under tension produces practically constant torsional resistance, notwithstanding the wear of the friction washers.

In my construction 1 have 'preferably adopted a ratchet-wheel having relativelylarge strong teeth which react against stationary detents; in association with which I employ a spring-controlled means for obtaining a yielding connection with the riliebar.

My invention furtherconsists in putting the ratchet wheel loose on the rifle-bar, and

interposing between them, certain elastic pressure devices that engage both the riflebar and the ratchet i wheel, and prevent movement between the-m when the normal torsional force iseXerted, but which yields when this normal torsional force-is somewhat exceeded. This predetermined resistance to movement between the elements above mentioned is preferably secured by a clutch whose elements are held in yielding engagement by a helical spring, as will hereafter be set forth.

ln the accompanying drawings Figure l is a vertical longitudinal section of a rock drill equipped with my device using a corrugated.

rosette clutch whose elements are held in engagement by a vhelical spring; Fig. 2 is a section on line 2-2of Fig. 1 showing the pawls that engage the ratchet wheel; Fig. 3 shows a riiie-bar equipped -with a clutch whose elements are held in working engagement by the winding up of the helical spring 30; Fig. 4 shows side and end details of the ratchet wheel of Fig. 3; Fig. 5 shows similar details of therifle-bar collar of Fig. 3; Fig. ,6 is a detail of the ratchet wheel spring of Fig. 3;` Fig. 7 is a vertical longitudinal section of a rock drill equipped with my device in which VaV cone clutch backed by a spring is used lto limit the torsional force to rotate the drill; Fig. 8 is a section on line 8-8 of Fig. 7 Fig. 9 is a detailed longitudinal section of the ratchet wheel shown in Fig. 9; Fig. 10 is a detailed side and end view of the ratchet wheel L12 of Fig. 9; Fig.

Patented Sept. 14, 1.91.5.l

11 shows similar details of the clutch of Fig. 1 -1 7; Fig. 12 shows a side view ofthe sliding rosettecollar; Fig. 13 is an end view ofthe sliding rosette collar; Fig. 14C shows the rosette clutch in the act of slipping the engagement with the ratchet wheel.

Similar characters denote similar parts throughout the several views.

My invention is here shown in connection with a rock drill cylinder that has no valve and is operated by reciprocating columns of air. But the invention is equally applicable to those-rock drills that are provided with anair valve.

In the cylinder 2O of Fig. 1 reciprocates the piston 21 that mounts the drilling tool in a well known manner. Sliding longitudinally in the piston head is the riie-bar 22 that engages the rifle-nut 23 secured in the piston in the ordinary manner. The ratchet wheel 52 is made separate from the rifle-bar ever, does not rotate appreciably as there is no force applied thereto, causing it to do so. y On the return or backward stroke of the piston the pawls 24 prevent the ratchet wheel 52 and the riiie-bar from turning backward, so thev riie-bar remains stationary and the piston is given a partial revolution by the spiral groove in the riie-bar, engaging the rifle-nut 23 in the piston. |Thus the turning is continued in a step by step motion, at each backward stroke or' the piston. kBut voccasionally it happens that on account of a seam in the rock or other cause, it may require such unusual force to rotate the drill as might break some part of the rotative mechanism. To prevent this, the ratchet wheel 52 is made separate from the rifle-bar 22, on which it is mounted.

The yielding device between the ratchet wheel and rifle-bar may vary in its details. In Fig. V1 the ratchet wheel 52 is combined with a rosette collar 50 that normally is kept in contact with the ratchet wheel 52 by the spring 53. The Sliding collar 50 is Splined to the rifle-bar 22. The surface of the teeth 51 are formed slanting so that when a suiiicient torsional force is applied to the ratchet wheel the sliding collar 50 is pushed longitudinally on the rifle-bar out of engagement with the ratchet wheel (see Fig. 14). The magnitude of the force that is required to slide the collar 50 out of engagement is governed by the tension of the spring 53 and the inclination or" the teeth of the clutch 51. These are so adjusted as to allow the rille-bar to rotate in both directions in-V side the ratchet wheel 52 when the rotative eHort is somewhat in excess of the normal working force.

In Fig. 7 the cone 40 is splined onto the rifle bar, to prevent rotation and is preferably faced with ber 4l to increase the friction Where it bears against the recessed ratchet wheel 42. 'Ihe degree of tension of the spring 43 limits the rotative force applied to the rifle-bar and eliminates the frequent adjustment of the frictional pressure. The pawls that engage the ratchet, are the same as shown in Fig. 2, or may be any other suitable kind known in the art. Il' from any cause, the torsional force required to rotate the drill becomes excessive, the cone 40 slips in the ratchet wheel 42 and allows the rifle bar to turn in the reverse direction, from that allowed by the pawls.

Figs. 3, 4, 5 and G illustrate a clutch whose teeth 28 and 29 are held in normal engagement by the winding up of spring 30. The collar 26 is secured on the end of the riflebar by the key 27. Formed on thecollar 26 is the tooth 28 that engages with the corre- Y sponding tooth 29 on the ratchet wheel 19.

The spring 30 has one end secured in the hole 31 of the ratchet wheel and the other end in the hole 32 of the collar 26. The

springS-O is placed under sufficient initial tension to keep the teeth 28 and 29 in driving contact when the rifle-bar exerts the tor-` sional force necessary for the normal rotation of the drill.V vBut if it should exert a greater force to Vrotate the drill than that given by such initial tension to wind up the spring to its normal working tension, the spring will be wound still tighterv and the teeth 28 and 29 will'be separated Yby the rifle-bar rotating in both directions inside the ratchetV wheel without revolving Athe drill. But the rifle-bar and mechanism kof rotation will thus be'saved from the break- Y said rifle-bar, a pawl engaging the ratchet wheel and allowing its rotation in one direction only, a driving engagement consisting of a'sleeve on said rile-bar non-revoluble therewith and engaging saidratchet wheel,

and a spring holding said kratchet wheel and sleeve in forced engagement under normal working stress but allowing their disengagement when abnormal torsional stress is applied to separate said engaging parts.

2. In a rock drill the combination with the actuating cylinder, of a piston in said cylinder, a rotating` deviceconsisting of a rifle-bar engagingsaid piston, a ratchetwheel loosely mounted on the rifle-bar, yielding clutch elements interposed between the ratchet-wheel and rifle-bar, a helical spring holding said clutch elements in forced engagement independent of the rotary eii'ort, and means for engaging the ratchet-wheel and vallowing its rotation in one direction only.

3. In a machine of the class described, the combination with the actuating cylinder, of a piston in said cylinder, aV rotating device consisting of a riie-bar engaging said piston, a ratchet-wheel loosely mounted on the rifle-bar, rosette teeth on the end of said ratchetwheel, a rosette collar yieldingly held in engagement with said ratchet-wheel andprevented from rotation on saidrii'lebar, Vand means for preventing said ratchetwheel from revolvingin one direction but allowing it to rotate inthe opposite direc- 131011. l y:

4. In machines of the class described the combination with the actuating cylinder, of

a piston in Vsaid cylinder, a rotating device consisting of a rifle-bar engaging said piston, a ratchet Wheel loosely mounted on the ri1e-bar, rosette teeth on the end of said ratchet Wheel, a rosette collar splined on the riie-bar, a spring adapted to hold the rosette collar in engagement With the ratchet-Wheel, and means for preventing the ratchet Wheel from revolving in one direction only.

5. In machines of the class described, the combination with the actuating cylinder, of a piston in said cylinder, a rifle-nut in said piston, a rotating device consisting of a rifle-bar engaging said rifle-nut, a ratchet- Wheel peripherally toothed and loosely mounted on the rifle-bar, rosette teeth on the end of said ratchet-Wheel, a rosette-collar yieldingly held in forced engagement With the ratchetevvheel, a nut screwed on the rifle-bar, a spring between said nut and rosette collar, and means engaging the peripheral teeth of the ratchet-Wheel to prevent its rotation in one direction only.

In testimony whereof, I sign the foregoing specification, in the presence of tvvo Witnesses.

CHARLES OTIS PALMER. Vitnesses:

B. C. BROWN, N. MGDONNELL.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C.

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